Metal structure



April l1, 1950 F. RATAlczzAK` 2,503,595

METAL STRUCTURE Filed May 19, 1944- I 2 Sheets- Sheet 1 April 11, 1950 F. 1. RATAlczAK METAL STRUCTURE 2 Sheets-Sheet 2 Filed May `19, 1944 IN V EN TOR.

Patented pr. ll, Q

METAL STRUCTURE Francis I. Rataiczak, Dayton, Ohio, ass'ignor to' General Motors Corporation, Dayton, Ohio, a

corporation of Delaware Application May 19, 1944, Serial No. 536,229

7 Claims.

This invention relates to metal structure and more particularly to an improved machine gun construction.

One object of this invention is to provide a low cost machine gun capable of firing high powered (iO-caliber ammunition.

` Another object of this invention is to improve upon the receiver construction so as to make a strong light weight receiver suitable for mass production.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a side elevational view of a gun embodying my invention;

Fig. 2 is a side elevational view similar to Fig. 1 but showing the breech cover r-aised;

Fig. 3 is a top View of the gun;

Fig. 4 is a plan view showing the construction of the receiver;

Fig. 5 is an elevational View of the receiver;

Fig. 6 is a sectional view taken on line 6-6 of Fig. 5;

Fig. 7 is a sectional view taken on line 'l-l of Fig. 5;

Fig. 8 is a sectional View taken on line 8-8 of Fig. 5;

Fig. 9 is a sectional view taken on line 9 0 of Fig. 5;

Fig. 10 is a sectional view taken on line |0|0 of Fig. 5

Fig. 1l is a front end elevational view of the receiver shown in Figs. 4 and 5.

Referring now to Figs. 1, 2 and 3 of the drawing, reference numerals 50 and 52 designate the breech housing and barrel respectively of a 60- caliber rapid lire machine gun. Reference numeral 54 designates generally the cover for the breech housing which is pivotally secured to the breech housing at 56. A belt feed mechanism 58 is removably secured to thecover member 54. The feedway 60 which is secured to the breech housing or receiver 50 cooperates with the belt feed mechanism 5B to direct the feed belt and the cartridges carried thereby into the breech housing 5D.

Reference numeral 64 designates generally an adapter which is used for mounting the gun and which incorporates a standard buffer arrangement, the details of which form no part of my invention and will not be described in detail. The cover 54 may be latched in its downward position by the cover latch (not shown) which engages the cover latch strike 60 carried by the breech housing 50. The latch is operated by means of the handle 10 (Figs. 1, 2 and 3) which is arranged as shown.

The breech housing 50 (Figs. 4-11) is made up in a novel manner in that it comprises a pair of stamped sheet metal elements |30 and |32 and a pair of end pieces |36 and |40 as best shown in Figs. 4 through 11. -These two stamped sheet metal elements are individually formed in the required shape, and are thereafter fitted lwithin one another as shown and are riveted together by means of a plurality of rivets such as the rivets |34 which are primarily used to hold the parts in proper assembled relationship during subsequent manufacturing operations on the breech housing or receiver assembly. Figs. 4 through 11 show the parts in an intermediate stage of completion. The end piece |36 is secured to the stampings by means of suitable screws .|38 arranged as shown in Figs. 5 and 6. A relatively heavy front end element |40 is riveted to the stamping |30 as shown in Fig. 10. After the various parts which make up the breech or receiver housing 50 have .all been riveted or screwed together, the assembly is hydrogen brazed, whereby all of the parts shown in Figs. 4 through 11 become the equivalent of one integral piece. By virtue of the above described arrangement, the amount of material required in the manufacture of the breech housing or receiver has been very materially reduced, and the weight of the breech housing or receiver has likewise been rvery materially reduced. Thus, with this type of construction it is possible to make the receiver strong without making it bulky. Another advantage of the arrangement shown in Figs. 4-11 is that the time required in forming the various guide channels and the like has been materially reduced since the need for hogging out a large amount of metal from a large forging or piece of bar stock has been eliminated. Subsequent to the hydrogen brazing operation, many or all of the heads of the rivets |34 may be ground off so as to provide smooth surfaces.

The relatively heavy end pieces |36 and |40 serve to reinforce the lighter weight stampings at the ends thereof `and also provide rigid mounting members which may be machined the same as if the entire breech housing were made from a large piece of heavy bar stock.

As best shown in Figs. '7 through 11, the inner stamping |32 is provided with opposed ledges |42 which serve to guide the bolt assembly generally designated by the reference numeral |50. The rear end piece |36 is suitably machined so as to serve as the housing for the bolt buier mechanism. Since the bolt buffer mechanism which comprises a plurality of concentric springs is of standard construction and since the details thereof form no part of this invention, other than the manner in which the element |36 is formed and held in place, the bolt buier mechanism will not be described in greater detail.

The ejected shells leave the breech housing 50 through the bottom opening |99.

The bolt (not shown) has an upwardly extending lug 209 ywhich is visible in Figs. 1 and 2. At the lback of the cover 54 is a hand engaging element 224 for hand cocking. The housing 252 of the feed rack support projects from opposite sides of the cover 54 as shown in Fig. 3. The guide plate 286 carried by the cover 54 helps to guide the cartridge into place.

It will be noted that the cover 54 is a sheet metal stamping. By virtue of the shape of the cover which comprises both ilat and rounded portions, the cover is inherently strong, yet light weight and inexpensive to manufacture.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood th-at other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

l. A receiver for use in a rapid fire machine gun comprising in combination, a pair of stamped sheet metal elements forming the main body of said receiver, one of said elements `comprising an outer element of substantially semicircular cross section, the other of said elements comprising an inner member substantially U-shaped in section with the upper ends of the arms of the U offset outwardly so as to engage the outer semicircular member and so as to provide substantially horizontal surfaces for guiding a reciprocating breech bolt.

2. In a rapid re machine gun, a receiver for guiding the breech bolt of the gun comprising in combination a pair of stamped sheet metal elements, at least one of which is formed to provide a breech bolt guide channel, and the other of which serves to reinforce said breech bolt guide channel and forming therebetween a pair of longitudinally extending air passages.

3. A guide including an outer shell having a hollow substantially semi-cylindrical portion, an inner sheet metal member having a lower U- shaped portion, the bottom of the U-shaped portion contacting the bottom of the outer shell lfor the greater portion of its length, said inner sheet metal member having its opposite sides above the lower U-shaped portion extending horizontally outwardly until they contact the outer shell to form guide ledges, said inner member and the outer shell being fastened together at their contacting bottom portions and at the vcontacting surfaces of the outermost parts of the inner member and the outer shell.

4. A guide including an outer shell having a hollow substantially semi-cylindrical portion, an inner sheet metal member having a lower U- shaped portion, the bottom of the U-shaped portion contacting the bottom of the outer shell for the greater portion of `its length, said inner sheet metal member having its opposite sides above the lower U-shaped portion extending horizontally outwardly until they contact the outer shell to form guide ledges, said inner member having flanges at the outer edges of the guide ledges in contact with inner surfaces of the outer shell, said flanges being fastened to said outer shell.

5. A guide comprising an inner and an outer sheet metal element, said inner sheet metal element having a lower U-shaped portion, the bottom of the U-shaped portion contacting the outer sheet metal element for a substantial portion of its length, said inner sheet metal element having its opposite sides above the lower U-shaped portion extending horizontally outwardly until they contact the outer sheet metal element to form guide ledges, said inner and outer sheet metal elements being fastened together at their contacting bottom portions and at the contacting portions of the outermost parts of the inner and outer sheet metal elements.

6. A .receiver comprising inner and outer sheet metal elements, said inner sheet metal element having a lower U-shaped portion contacting the outer sheet metal element for a substantial portion of its length, said inner sheet metal element having those portions of its opposite sides above the lower U-shaped portion extending horizontally outwardly until they contact the cuter sheet metal element to form guide ledges, said outer sheets metal element extending around the bottom and side portions of the inner sheet metal element, said inner and outer sheet metal elements being fastened together at their contacting bottom portions and at the contacting portions of the outermost parts of the inner and outer sheet metal elements, and reinforcing end elements located within the end portions of the inner and outer elements and being tightly fastened to both the inner and outer elements to reinforce them and complete the receiver.

7. A guide comprising an inner and an outer sheet metal element, said inner sheet metal element having a lower U-shaped portion, the bottom of the U-shaped portion contacting the outer sheet metal element, said inner sheet metal element having its opposite sides above the lower U-shaped portion extending horizontally outwardly until they contact the outer sheet metal element to form guide ledges, a portion of the bottom of the inner element being open and having at the sides of said open portion substantially vertical walls extending downwardly from said guide ledges, said outer sheet metal element extending into contact with said substantially vertical walls, said inner and outer elements being fastened together at their contacting portions. FRANCIS I. RA'IAICZAK.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,007,911 'Bjorgum Nov. 7, 1911 1,431,057 Sutter Oct. 3, 1922 1,509,401 Gorton Sept. 22, 1924 1,845,242 Coupland Feb. 16, 1932 2,050,038 Browning Aug. 4, 1936 2,093,704 Browning Sept. 21, 1937 2,101,086 Moore Dec. 7, 1937 2,113,202 Stange Apr. 5, 1,938 2,137,808 Pugsley Nov. v22, 1,938 2,146,743 Johnson Feb. A14, V1939 2,177,991 Maddock Oct. 31, 1939 2,326,283 Bonsall Aug. 10, 1943 2,345,127 Kehne Mar. 28, 1944 FOREIGN PATENTS Number Country Date 562,476 Germany Oct. 26, 1932 191,038 Switzerland Aug. 2, 1937 Certificate of Correction Patent No. 2,503,596 April 11, 195o FRANCIS I. RATAICZAK It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column l, line 60, after the Word and period shown insert the following paragraph:

and that the said Letters Patent should be read With this correction therein that the N same rnay conform to the record of the case in the Patent Office.

Signed and sealed this 11th day of July, A. D. 1950.

[SEAL] THOMAS F. MURPHY,

Assistant ommz'gsz'oner of Patents.

Certificate of Correction Patent No. 2,503,596 April 11, 195o FRANCIS I. RATAICZAK It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column l, line 60, after the Word and period shown." insert the following paragraph:

[SEAL] THOMAS F. MURPHY,

Assistant Uommz'saz'oner of Patents. 

